The issue of having a common centralized database for a diversity of applications in the field of Telecom networks is addressed. Most of Telecom networks, supporting a variety of different generations of telecommunication systems, being wireline or wireless systems, conventionally make use of one or more common centralized databases to store subscription and subscriber data as well as service data for a variety of applications residing in the Telecommunication network or in a 3rd party service network but accessible to subscribers of the Telecom network.
As the Telecom networks grow, newer generations of telecommunication systems turn up and the existing common centralized databases are not always adaptable to, or suitable to fit, the needs of all telecommunication systems in a Telecom network. Nevertheless, Telecom networks share quite similar requirements to be fulfilled by any particular database system usable therein.
A conventional and centralized Telecom database is generally required to support, at least, the following characteristics: resiliency and high availability; consistency; high performance and low latency; high capacity; scalability; geographical redundancy; flexible deployment and data model; single point of access (one in each geographical location); and no single point of failure.
In this respect, geographical redundancy for a conventional and centralized Telecom database has generally been understood as having a replicated node in addition to a main node, the main node being the operative one and the replicated node being on stand-by to resume the operations in case the main node goes down for any reason.
Nowadays, a purely centralized database, amongst other drawbacks, is quite costly in terms of signalling transport; and, in practice, the usage of its resources is not well balanced, since the variety of application data makes some data to be accessed more frequently than others. Regarding the geographical location where the centralized database is located, the choice may be quite significant on the costs of signalling transport, both on economical terms as well as on load and risk of failure terms. Obviously, the longer the signalling path is between a database client and the database itself the more risk exists of encountering a node unable to further submit the signalling towards its final destination. Likewise, the longer this signalling path is the more load the Telecom network supports and the longer execution times. Apart from that, the Telecom networks are nowadays spread through different and far territories often communicated through different access networks belonging to other network operators; in this scenario, the longer this signalling path is the more network operators may be involved and more costs are derivable thereof.
On the other hand, as exploring other technologies, a distributed database may be regarded as a plurality of databases physically or logically distributed, likely under control of a central database management system, and wherein storage devices are not all necessarily attached to a common processing unit. Thus, the distributed database might be built up with multiple computers located in the same physical location, or may be dispersed over a network of interconnected computers.
Generally speaking, the distribution of database instances is not necessarily a consequence of data distribution itself but is beneficial for the purpose of data replication in order to obtain high available systems and for geographical redundancy. More particularly, a so-called Data Layer Architecture technology, which replaces the conventional centralized database system by a number of Telecom database front-ends accessing to a common back-end, the back-end being centralized or distributed, is an exemplary applicability of a distributed database fulfilling the above requirements for a Telecom database and usable for data distribution and replication.
The replication of data in different database instances of a distributed database requires a complex management to keep the existent replicas up-to-date in the different database instances. Moreover, clients of conventionally distributed databases in the field of Telecom networks cannot always be able to perform any database-related operation in a closer database instance, thus not always minimizing the signalling path required for said database-related operation. Furthermore, clients of conventionally distributed databases in the field of Telecom networks may experience trouble to access data where any database instance is unavailable.